ICS9169C-271

www.DataSheet4U.com Integrated Circuit Systems, Inc. ICS9169C-271 Frequency Generator for Pentium™ Based Systems General Description The ICS9169C-271 is a low-cost frequency generator designed specifically for Pentium based chip set systems. The integrated buffer minimizes skew and provides all the clocks required. A 14.318 MHz XTAL oscillator provides the reference clock to generate standard Pentium frequencies. The CPU clock makes gradual frequency transitions without violating the PLL timing of internal microprocessor clock multipliers. A raised frequency setting of 68.5MHz is available for Turbo-mode of the 66.8MHz CPU. The ICS9169C-271 contains 12 CPU clocks, 4 PCI clocks, 1 REF at 48MHz and 1 at 24MHz. The twelve CPU clock outputs provide sufficient clocks for the CPU, chip set, memory and up to two DIMM connectors (with four clocks to each DIMM). Either synchronous(CPU/ 2) or asynchronous (32 MHz) PCI bus operation can be selected by latching data on the BSEL input. Features Twelve selectable CPU clocks operate up to 83.3MHz Maximum CPU jitter of ± 200ps Six BUS clocks support sync or async bus operation ±250ps skew for all synchronous clock edges CPU clocks BUS clocks skew 1-4ns (CPU early) Integrated buffer outputs drive up to 30pF loads 3.0V - 3.7V supply range, CPU(1:12) outputs 2.5V(2.375-2.62V) VDD option 32-pin SOIC/SOJ package Logic inputs latched at Power-On for frequency selection saving pins as Input/Output 48 MHz clock for USB suppor...